A great number of seats have been developed, particularly for cyclists, which are intended to improve the comfort of the rider. Much attention has been devoted to improving the cushioning or resiliency of the seat by providing an improved suspension associated with the seat or a more forgiving padding in the seat itself.
To a large extent, a cyclist's discomfort arises because the cyclist is not static and the buttocks are constantly moving relative to the seat. This problem is partly addressed in prior art devices where the seat is made in two portions which are independently movable, each portion being adapted to alternately support one of the buttocks. An example of such a structure is shown in U.S. Pat. No. 604,347, where the seat portions are each mounted to a support which is horizontally disposed in normal use and the seat portions alternately rotate in a vertical plane about the support when a rider is pedalling. Such seats are nevertheless unsatisfactory unless they can be customized to an exacting shape which conforms to the rider's anatomy.
Some effort has been made in U.S. Pat. No. 4,387,925 to provide such a seat structure in which the seat portions are shaped to alternately give support to the rider's buttock in a concave portion and to the rider's upper leg in a convex portion. While said seat structure does not give any support during weight transfer as the rider pedals, it is a marked improvement over the seat structure shown in U.S. Pat. No. 588,039 where a pair of seat cups are horizontally disposed for rotation in a horizontal plane about respective vertical mounts secured to a horizontally-arranged table which likewise is rotatable in a horizontal plane. The only consideration given to the rider's shifting weight during pedalling is a hinged connection between the seat cups and their respective vertical mounts. Again, there is no continuous support during weight transfer of the rider.
An object of this invention is to provide an improved mounting structure for attaching the seat to the cycle frame in which any relative motion between the rider and the seat is minimized so that the rider will be more comfortable and safe from injury.